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There have been 318 items by azrael (Search limited from 04-September 93)
Foam like that will result in a tighter barrel fit for spring based blasters and thus have more even air delivery and a better air seal.
As for stefans being more accurate, I would say...it depends. Accuracy depends on a good amount of weight being forward loaded, around 1g.
I have had the best luck with 1.3g tips, as far as accuracy goes. Many types of stefans weigh 1g total, which IMO, is too light.
I'm using slugs with #8 washers, and they are pretty straight, but I haven't tested at long range, either. Right now MHA foam is a little tight for my PETG barrel, so I can't compare.
However, when using MHA foam and AMIOR style darts, I preferred my PAK D silicone tips with my 50mm dart length compared to normal or even 50mm AMIORs. When using my brassed bolt equipped EAT. Granted, the PAK D is a little thicker, but I dunno.
It could also be that springers and airguns work better with different kinds of dart tips.
I'm going off this thread, btw:
Some darts are coming in under a gram, and that's for total dart mass. I don't think that's enough.
Never been to a Nerf War that's been organized within the NIC. What kind of blasters can I expect to see there?
W - e
A - lways
R - ecommend
M - eeting
U - nder
P - retenses
When: June 15th 10:00 am - 4:30ish pm
Where: Santiago Park, Santa Ana
What to bring:
Money or food
A good attitude
The usual socal rules still apply.
Questions? post them here.
Trying to get a feel for how prepared I would have to be, you know?
Oh if you bring the tanks we talked about, I can buy them there. If I can convince my buddy to come with, that is haha.
I'll try to be at this one. I think my dad wants to have a barbeque or something, but I'll see if he can move it to the next day.
Oh cool. That's great. What kind of turnout do you get?
You should expect to see less homemades than in most war photos from other parts of the country.
Some people even bring stock blasters and darts. Doesn't stop them from having fun though.
My friend and I use just modified Nerf blasters mostly. Higher spring load, brassed bolts. Modified flywheel setups. Getting an inkling to build a homemade though hahah.
I haven't done it, but it's not rubbery kind. I have seen it used on drum sticks and golf grips, myself. I don't know the proper name for it.
Athletic tape actually sounds like it would be much worse. Instead of just pealing off, it would leave a sticky mess on the flywheels.
I can run mine off 4s/16.8v, with a LiPo battery, with around 9-11kg spring resistance, FWIW.
You're absolutely going to need to put in the upgraded spring if you up the voltage. That will honestly probably solve your problem. Run is 3s, with the new spring.
If it's like a USB, which would make sense, it would be 5V.
Do you know what the voltage is on these things?
How much are they?
EDIT: Looks like it can supply 800-1000mA depending on who makes it. I don't know if that's a continuous figure or max rating or what.
You're better off getting a 2s LiPo or NiCD pack with a high mAH. As I recall, you're not overvolting it, really, right?
For example, I use a 1s LiPo with my Stryfe and it lasts forever. 4300mAH (I had a 6000mAH before, haha).
In an air blaster, the tank stores air, meaning that the air in that system is already at its maximum pressure. A loose fit will take the most advantage of this stored energy.
That is a VERY clear indication that your AA tray does not work, either because of your solder, or because of the tray.
I'm using unprotected (gray) trustfire batteries.
Testing the solder joints, they provide negligible resistance alongside the metal plates, though I don't know if this is relevant.
When firing with 6 D batteries, the voltage across the two panels on the battery sled dips slightly from 9 to about 8. When attempting to fire with the trustfire batteries, it drops to 0 volts.
Wrong, the spring has a high resistance, and should not be soldered to. Excessive current draw can cause it to light on fire. This is a well documented problem with battery springs. Ideally, battery trays shouldn't use springs at all.
Dude, as already pointed out, your battery connector is connected to the battery sled in the wrong polarity.
The black wire should go to the spring.
The red wire to the tab.
There is no thermistor in the battery sled.
It should not matter if you solder the wires to the spring and tab, so long as the join is good and clean.
No other electrical mods are needed unless you want to remove all of the locks.
And the solder isn't about age, it's about technique and what type of solder it is. Still haven't mentioned the type of soldering iron (wattage mostly) and solder alloy.
If your technique isn't good, your solder joints will not be good. I can't tell from that pic is your solder joints are good, but it looks like the solder did not wet on the contact at all. Meaning not really all that good.
EDIT: Wait, what batteries are you using? Are they unprotected or protected Trustfores? Protected ones will not work.
I doubt that is what it is, though.
I don't know the dimensions of the spring, and I don't really care too much, but here's some math from a flashlight forum:
That should give you an idea, at least.
Looking at #24 gauge bare copper wire which has almost the same
diameter as 0.022 inch wire, the resistance for 1000 ft is 20.8 ohms.
For 1 foot, it's 0.0208, and for 1 inch it's 0.001733 ohms.
The length of the helix is approx:
L=4.5 turns times 0.375 inches times pi=5.3 inches.
The increase in length due to the helix over the
circumference is only about 0.2 percent, so this increase
will be ignored.
5.3 inches times 0.001733 equals 0.00918 ohms total for a copper spring.
Knowing that the resistivity of SS is about 42.4 times higher than
copper, multiplying the total resistance times 42.4 gives us an
estimate of the total resistance of the SS spring.
R(SS)=0.00918 times 42.4 which equals 0.39 ohms total.
This number indicates something went wrong with the previous
calculation done in the previous post. I suggest checking
it for an error involving the conversion factors. Since rho
is given in ohm-cm i suggest working entirely in cm and cm^2
and redo the calculations.
You are underestimating stall current, meaning the current that a motor uses when it starts moving. It can be pretty big, depending on how many volts you're feeding the motor. As you increase the voltage, the current demanded by the motor increases too.
It's a pretty well documented phenomenon in in flashlight forums. MY WIRE wouldn't catch fire under those circumstances, I use teflon insulated stuff, it's pretty tough stuff. Also, my spring HAS gotten hot enough to catch flame. I had to put out my Stampede - this happened to me. Why doubt me?
I don't know anything about yours. I've used slightly higher gauges of this teflon insulated wire in robotic builds that consume over 100A at stall current. And it was fine.
You might be fine because Trustfires are honestly terrible batteries that cannot supply the current that these motors need. They have a poor discharge rating. If you use something that actually gives the motor what it needs, it is a different story. My rate of fire is higher than most 4s (16.8v) Stampedes I have seen with a similar spring load (I am approaching 10-11kg).
Or at least solder to the metal plate and not the spring. Or solder a crap load of wire or something to the spring to increase the area. That will reduce resistance.
As far as trustfires doing that, I would say that's more due to overdischarging the cell or shorting the battery. Trustfires have terrible current discharge rates. Well below what most powerful motors need at stall. When using any kind of powerful battery, you should always install a simple LED voltmeter to prevent overdischarge.
Not that a AA tray's battery retention springs are any better haha.
Your most obvious test since you have a multimeter is to make the tray functions. Are you measuring 16.8 volts from it on a full charge?
Let's make it useful, at least.
Are you sure there's no corrosion or anything that could mess up the contacts? Have you considered that you may have a cold solder joint? Cold solder joints are a poor electrical connection.
What solder and soldering iron did you use?
I love the physics documents that Doom wrote up, I was stoked to find that. There should be more of a scientific approach to things, at least in testing.
For me, the biggest advantage of write ups is less leg work. I can see what has been done, learn what materials to use and where I can buy them. I can learn from both past triumphs and mistakes.
Where the heck are you thinking of mounting it? Haha.
If you're thinking about the barrel, it doesn't really matter if you seal it right. Besides, any "air loss" argument is moot if you haven't done a full seal bolt/barrel setup with something like brass, anyway. Tons or air being lost from that big old plunger in that case.
I don't know that a switch to detect plunger travel will work all that well, maybe an IR sensor? That's how I would do it.
There's been other builds that use Arduinos for ammo counting, so it's not the first "Arduino powered" mod.
I just don't understand how there isn't TONS of space. You only need a 5mm IR LED and a 5mm phototransistor. That's tiny. There's plenty of places to mount them that will register a complete cycle, if you add the correct delay to allow for spring return and such.
Well google lied to me then. >:|
But I suppose mine is a lot more compact than the top result. As for your other question if air is meaningless here then there's a nice empty space below the barrel perfect for a small sensor. Figure if I seal it up with some acrylic there shouldn't be too much of a loss.
And Zorn, you can close the topic if you'd like. I wasn't aware that logs were extremely erotic here.